VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Avionics / Interiors / Fiberglass > Electrical Systems
Register FAQ Members List Calendar Today's Posts

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 05-02-2017, 08:05 PM
rapid_ascent rapid_ascent is offline
 
Join Date: Mar 2008
Location: Dublin, CA
Posts: 1,261
Default

Lots of stories on VAF about failed alternators. Batteries are a maintanence item that can have a low probability of failure if properly maintained. I plan a dual alternator system. I may have a small secondary battery too but my first line of defense is the backup alternator.
__________________
Ray Tonks
2020 Donation Paid
Titan IOX-370, Dual PMAGs, 9.6:1 Pistons, FM-150
RV-7 Fuselage in progress
* Cabin Interior - In progress
RV-7 SB Wings
* Both Wings fully skinned
* Fuel Tanks Complete - No leaks finally
* Ailerons Complete
* Flaps Complete
RV-7 Empennage - Complete (a little fiberglass work left)
Vans Training Kit # 2 - Complete
RV-7 Preview Plans
Vans Training Kit #1 - Complete
EAA Sheet Metal Class - Complete
Reply With Quote
  #12  
Old 05-02-2017, 08:43 PM
Bevan Bevan is offline
 
Join Date: Sep 2007
Location: BC
Posts: 1,674
Default

Batteries degrade (fail) slowly over time in that they store less useable energy, and yet we still fly with them never really knowing their capacity at that particular time.
__________________
RV7A Flying since 2015
O-360-A1F6 (parallel valve) 180HP
Dual P-mags
Precision F.I. with AP purge valve
Vinyl Wrapped Exterior
Grand Rapids EFIS
Located in western Canada
Reply With Quote
  #13  
Old 05-02-2017, 09:34 PM
AlexPeterson's Avatar
AlexPeterson AlexPeterson is offline
 
Join Date: Sep 2005
Location: Maple Grove, MN
Posts: 2,333
Default two alternators vs two batteries

It also depends also on the type of ignition one has. I have dual lightspeed ignitions, so I prefer two batteries. I have a setup to test the backup battery (whose only function is to feed the second ignition) using a 12v lamp. This draws a known current, so I can calculate the effective amp-hrs available until it drops to some specific voltage. I test it annually.
__________________
Alex Peterson
RV6A N66AP 1700+ hours
KADC, Wadena, MN
Reply With Quote
  #14  
Old 05-03-2017, 05:26 AM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 9,500
Default

There is no one answer.

I entirely agree with the dual alternator strategy for an IFR bird, and lean toward dual alt/dual battery for EFI/EI.

That said, the KIS approach to VFR with a low-draw (<1 amp) electronic ignition is a small secondary battery. KIS is good.
__________________
Dan Horton
RV-8 SS
Barrett IO-390
Reply With Quote
  #15  
Old 05-03-2017, 05:37 AM
vic syracuse vic syracuse is offline
Super Moderator
 
Join Date: May 2005
Location: Locust Grove, GA
Posts: 2,626
Default

Quote:
Originally Posted by AlexPeterson View Post
It also depends also on the type of ignition one has. I have dual lightspeed ignitions, so I prefer two batteries. I have a setup to test the backup battery (whose only function is to feed the second ignition) using a 12v lamp. This draws a known current, so I can calculate the effective amp-hrs available until it drops to some specific voltage. I test it annually.
For those with dual electronic ignitions I would encourage you to check the backup battery as often as possible, certainly more than once per year. I have seen more than one airplane come through my shop with the backup battery reading 5 volts! Sometimes it was due to a charging system failure and sometimes it was a corroded connector on the battery. Klaus has a schematic that allows you to test the backup battery prior to takeoff.

Vic
__________________
Vic Syracuse

Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P/IA, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
Kitplanes "Unairworthy" monthly feature
EAA Sport Aviation "Checkpoints" column
EAA Homebuilt Council Chair/member EAA BOD
Author "Pre-Buy Guide for Amateur-Built Aircraft"
www.Baselegaviation.com
Reply With Quote
  #16  
Old 05-03-2017, 07:10 AM
AlexPeterson's Avatar
AlexPeterson AlexPeterson is offline
 
Join Date: Sep 2005
Location: Maple Grove, MN
Posts: 2,333
Default

Quote:
Originally Posted by vic syracuse View Post
For those with dual electronic ignitions I would encourage you to check the backup battery as often as possible, certainly more than once per year. I have seen more than one airplane come through my shop with the backup battery reading 5 volts! Sometimes it was due to a charging system failure and sometimes it was a corroded connector on the battery. Klaus has a schematic that allows you to test the backup battery prior to takeoff.

Vic
Good point - I do check the voltage of this battery prior to startup before every flight. I also full time monitor its voltage during flight to be sure the proper charging voltage is being applied. The test I do annually is a capacity check, where I run it down to perhaps 10 volts, to determine amp-hr capacity.
__________________
Alex Peterson
RV6A N66AP 1700+ hours
KADC, Wadena, MN
Reply With Quote
  #17  
Old 05-03-2017, 07:16 AM
Veetail88's Avatar
Veetail88 Veetail88 is offline
 
Join Date: Oct 2008
Location: Hales Corners, WI
Posts: 981
Default

You should check with Rosie about this, but read his Carribean trip thread first!
__________________
Jesse Bentley
N229Z - RV-8 - Flying - Livin' the dream!
Reply With Quote
  #18  
Old 05-03-2017, 10:19 AM
JHartline JHartline is offline
 
Join Date: Dec 2012
Location: Carrollton, GA 5GA2
Posts: 259
Default Thank you all for the replies

I feel like the available backup-battery solutions are getting better but maybe not the ideal situation for me just yet. And the points about how to avoid getting stranded somewhere are well made. While my mission won't take me into austere locations we have all seen how deserted ramps are late on a weekend evening when we're trying to get home.

I will be talking with Stein very soon and I'm sure he will provide some great options to consider. Thanks for the input - it is always valuable and always appreciated.
__________________
James Hartline
Carrollton, GA 5GA2
RV-14 - First flight 4/7/2019. Phase I complete as of 9/11/2019!!
Reply With Quote
  #19  
Old 05-03-2017, 11:43 AM
vic syracuse vic syracuse is offline
Super Moderator
 
Join Date: May 2005
Location: Locust Grove, GA
Posts: 2,626
Default Well done

Quote:
Originally Posted by AlexPeterson View Post
Good point - I do check the voltage of this battery prior to startup before every flight. I also full time monitor its voltage during flight to be sure the proper charging voltage is being applied. The test I do annually is a capacity check, where I run it down to perhaps 10 volts, to determine amp-hr capacity.
Well done!

Vic
__________________
Vic Syracuse

Built RV-4, RV-6, 2-RV-10's, RV-7A, RV-8, Prescott Pusher, Kitfox Model II, Kitfox Speedster, Kitfox 7 Super Sport, Just Superstol, DAR, A&P/IA, EAA Tech Counselor/Flight Advisor, CFII-ASMEL/ASES
Kitplanes "Unairworthy" monthly feature
EAA Sport Aviation "Checkpoints" column
EAA Homebuilt Council Chair/member EAA BOD
Author "Pre-Buy Guide for Amateur-Built Aircraft"
www.Baselegaviation.com
Reply With Quote
  #20  
Old 05-03-2017, 02:44 PM
DanH's Avatar
DanH DanH is offline
 
Join Date: Oct 2005
Location: 08A
Posts: 9,500
Default

Quote:
Originally Posted by vic syracuse View Post
Klaus has a schematic that allows you to test the backup battery prior to takeoff.
Vic, got a link? Found these two (both appear to be voltage monitoring)...

http://lightspeed-aero.com/Manuals/PS_Diagram.htm

http://lightspeed-aero.com/Images/du...ator-LSEr4.pdf

...but nothing to test battery capacity.

Re voltage monitoring, these are less than $5 delivered, and can be configured to alarm:

http://www.vansairforce.com/communit...&postcount=166
__________________
Dan Horton
RV-8 SS
Barrett IO-390
Reply With Quote
Reply



Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 01:54 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.